US2700279A - Refrigerating apparatus and water heater - Google Patents

Description

1955 c. A. STICKEL REFRIGERATING APPARATUS AND WATER HEATER Filed June 12, 1952 INVENTOR. Carl A. Sf/ckel BY VIII. liar United States Patent REFRIGERATING APPARATUS AND WATER HEATER Carl A. Stickel, Dayton, Ohio, assignor to General Motors Corporation, Dayton, Ohio, a corporation of Delaware I Application June 12, 1952, Serial No. 293,109

9 Claims. (Cl. 62-4) This invention relates to refrigerating apparatus and more particularly to the use of a single multiple-type refrigerating system for heating water, preserving frozen foods and cooling air.

A promising development is the use of refrigerating systems for heating water. It has been proposed to use the refrigerating effect of such a system for cooling air or for cooling a refrigerator. Either of these have certaln objections. In most places, the cooling of air is objectionable and wasteful during the colder months of the year. When used for a refrigerator, the suction pressure is so low that the volumetric efficiency of the compressor is low and the condenser temperature and the heat output are not sufficient for rapid water heating.

It is an object of my invention to so adopt and apply a single refrigerating system that it provides ample water heating and satisfactory food freezing and preserving with a minimum of air cooling and dehumidification.

It is another object of my invention to make such a system very economical, safe and reliable.

In the form illustrated, these objects are attalned by employing a multiple compressor either of the multiple efiect type or the multi-stage type. This compressor discharges into a condenser which is used for heating water. Part of the liquid refrigerant is evaporated at a low temperature in a refrigerator designed for freezing and preserving frozen foods and its evaporator outlet is connected to the low pressure suction inlet of the compressor. To insure an adequate supply of high pressure evaporated refrigerant which provides adequate water heating, the remainder of the liquid refrigerant is evaporated in an air cooling coil the outlet of which is connected to the high pressure inlet of the compressor. This coil may operate at a sufficiently low temperature that its cooling effect is largely applied to dehumidification of air.

water heating is nil, there is provided a cooling coil in a thermosiphon arrangement controlled by a thermostatic valve which opens when the heater reaches an excessively high temperature.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred form of the invention is clearly shown.

In the drawing the figure is a diagrammatic representation of a refrigerating system embodying one'form of my invention.

Referring now to the drawing there is shown a water heater 20, a home freezer 22 and an air cooling coil 24. Beneath the water heater there is provided a sealed motor-compressor unit 26 having a low pressure inlet port 28 and high pressure inlet port 30. This motorcompressor unit 26 may have a compressor of the multiple effect type such as is illustrated in Figures 21 to 24 of the Feicht Patent 2,299,811 issued October 27, 1942. The Feicht compressor above referred to has a low pressure inlet 414, a high pressure inlet 424 and an outlet 416. Instead of a multiple effect compressor, the sealed unit 26 may have a multi-stage compressor, for example like one disclosed in the Guild Patent Re. 21,196 issued To prevent overheating of the water when the demand for r September 5, 1939. This Guild compressor has a low pressure inlet port 19, a high pressure inlet port and an outlet 21.

The outlet 32 of the multiple compressor unit 26 is connected directly to the inner tube 34 of a double pipe condenser. The outer tube 36 of the double pipe conice denser has its upper end connected by a connection 38 to a chamber 40 provided in between the spaced bottom walls 42 and 44 of the heater 20. The side and top walls 46 of the heater 20 are surrounded by insulation 48 which may extend down and enclose the condenser 34 to 36. The chamber 40 forms a part of a secondary heat transfer circuit containing an efficient heat transfer fluid such as water. Water is circulated through the heat transfer circuit either by the principal of evaporation and condensation or by the electric pump 50 having its inlet connected by a pipe 52 with the bottom of the chamber 40 and its outlet connected by a pipe 54 to a water jacket 56 surrounded by the motor-compressor unit 26. The opposite portion of the water jacket 56 is connectedby the pipe 58 to the portion of the outer tube 36 at the bottom of the condenser 34 to 36.

The motor-compressor unit 26 is energized'by the supply conductors 60 and. 62 and the pump 50 is electrically connected in parallel circuit relationship with the motor-compressor unit 26 by the supply conductors 64 and 66 so that they will be simultaneously energized. Therefore, whenever the motor-compressor unit operates, the pump 50 will also operate to circulate the heat trans. fer liquid such as Water through the pipe 54, the water jacket 56, the pipe 58, the outer tube 36 of the condenser, the jacket 40, and the pipe 52. This will transfer the heat from the motor-compressor unit 26 and the condenser 34 to the jacket 40 and from the jacket 40 through the Wall 32 to the interior of the water heater tank 46. The use of this secondary circuit will prevent the liming of the condenser. The placing of the motor-compressor unit and the condenser and secondary heat transfer cit: cuit beneath the water heater 20 enclosed by the insulation 48 traps heat dissipated from the parts so that this heat will be available to prevent heat loss from the water heater tank 20.

The compressed refrigerant is condensed within the pipe 34 by the secondary heat transfer fluid which circulates around it and flows from its lowermost portion through a tube 68 to some form of flow control device such as a thermostatic expansion valve 70. The outlet of this thermostatic expansion valve 70 is connected to the tube enclosing a separating chamber 72. In this separating chamber the liquid refrigerant will collect at the bottom of the chamber and the flash gas will collect in the upper portion thereof.

To insure that the freezer 22 is always assured of a supply of liquid refrigerant, the bottom of the chamber 72 is connected by the pipe 74 to the inlet of a second thermostatic expansion valve 75 having its outlet connected to the inlet of the refrigerant evaporator coil 77 wrapped around the walls of the freezing compartment 79 of the freezer 22. The evaporator 77 and the walls 79 are surrounded by insulation 81 including the insulated removable top 83. The refrigerant coil 77is wrappedprogresslvely upwardly and at its uppermost part adja cent its outlet it has in heat exchange relationship the thermostat bulb 85 of the thermostatic expansionvalve 75. The outlet of the evaporator 77 is connected by the low pressure suction conduit 87 to the low pressure inlet 28 of the-compressor 26.

Inasmuch as it is desired that the freezer be-kept at:

a temperature of 0 F. or below, the suction pressure .of

the refrigerant from the freezer in the low pressure suction conduit -87 will be correspondingly low. If this: were thesole source of refrigerant available for heating the water in the 'water heater 20, the supply would 'be insufiicient and a very large compressor 'would be re-- quired to provide sufficient heat for the water heater 20. Therefore, to improve the elfectiveness of water heating, the air cooling coil 24 is provided. This air cooling coilmay be of any suitable type and is shown diagrammati-' eificiency of the-system and slightly reduce the'power requirement and increase the volumetric efficiency and capacity of the system. Any moisture condensedby the air-{cooling unit is collected in the pan 91 beneath and conducted to a drain through pipe 93. The outlet of the cooling unit 24'is connected by the high pressure suction conduit 95 tothe high pressure inlet 30 of the motor-compressor unit 26. The thermostatic expansion valve 70 has its thermostat bulbg97 located in heat transfer relationship with the outlet of the air cooling unit 24.

The operation of the motor-compressor unit 26 and the pump 5.0 is controlled by two thermostatic switches 121 and 123. The switch 121 is connected in the parallel circuit .125 connected to the supply conductors 127 and the conductors 60 and 66 while the switch 123 is connected in the parallel circuit 129 likewise connected vto the supply conductor 127 and the conductors 60 and 66. The other supply conductor 131 connects directly to the conductors 62 and 64. The thermostatic switch 121 has a thermostatic bulb 133 located in .heat exchange relationship with the wall 79 of the freezer 22. It is set to close at a temperature of about F. and to open at a temperature of about F. The switch 123 has its thermal element extending into the water tank 46 of the water heater '20 and is set to close when the water temperature in the water heater 20 reaches a selected temperature such as 140180 F. The switch 123 may be set to open when the temperature in the water heater reaches atemperature :of 145-185 F. as may be selected.

,In the event there is no demand for water heating by the water heater 20, there will remain a continued demand for refrigeration by the freezer 22. This situation might occur whenever the occupants of a residence are away for .any substantial length of time. Under such circumstances, the water in the Water heater 20 might become excessively hot. The water heater will of course be provided withthe usual safety pressure releasing valve and some heat may be dissipated through the water pipes. However, as a further protection I have provided a thermostatic valve 137 upon the hot water outlet pipe 139 of the water heater 20. This thermostatic valve 137 is set to open its side outlet when the water in the Water heater 20 reaches a dangerous temperature such as 200 F. The side outlet 'of this thermostatic valve 137 is connected to one end 139 of an air heating coil 141. The other end 143 of the air heating coil 141 is connected to the water inlet pipe 145 of the hot water heater 20 which extends substantially to the hot water tank 46; By this arrangement when the 'water in the tank 20 reaches the selected danger temperature such as ZOO" 'F., the valve 137 will open its side outlet and permit a thermosiphon circulation from the tank 46 through the connection 139, the air heating coil 141, and the connection 143 back into the 'tank 46. 'This will dissipate sufficient heat from the water in the tank to the air :to prevent the water heater from becoming overheated.

To provide air circulation for the air cooling unit 24 and the air-heatingcoil 141,- there is provided a duct 147 connectin'grthe-air cooling unit .24 with the "air heating coil Z141. duct '147 is provided with an electrically operated fan-,149econnected the conductors ISL-and 153 inparallel electric circuit relationship with the motor-compressor unit .26 and the pump 50. This will cause thefan 149 to circulate air .first through the air cooling unit 24 thence through the :duct ,in heat transfer relationship with .the .air heating coil 141 whenever the .refrigenating system operates. This-circulation increases the 'capacity,rof-:the:air cooling unit 24 andth-eair heating'cjoil .141. If this is -;not desired, it may :be stopped by Qpening the-switch 155.

Thissystem -:is economical in first cost :because= a single motor-compressor unit supplies all the "energy for heating water, freezing and preserving frozen foods and also air cooling and dehumidification. Preference is given to the -freezer-unit 'and to the water heating-unit so that the air cooling unit only supplies sufiicient refrigeration to make the system elficient and economical both in first cost and operating cost.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted as may come within the scope ofthe claims which follow.

What is claimed is as follows:

1. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures abovefreezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet continuously connected to the outlet of said freezing evaporator and a high pressure suction inlet continuously connected ;to;the outlet of said air cooling unit, said condenser having its inlet continuously connected to the outlet of said compressor, flow control means for controlling the flow of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said flow control means having a greater total restriction to flow to said freezing evaporatorthan to said air cooling-unit.

2. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including .a refrigerant condenser in heat exchange .relation with the liquid vto be heated, a multiple compressor "having a low pressure suction inlet connected to the outlet of said freezing evaporator and a high pressure suction inletconnected to .the outlet .of said air cooling unit, said condenser having its inlet connected to the outlet of said compressor, flow control means for controlling the how 'of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said how control means having a greater total restriction to flow to said freezing evaporator than to said air cooling unit, an air heating nnithaving its inlet and outlet connected to said liquid heating unit, and a thermostatic valve set to open at a predetermined high liquid temperature in said liquid heating unit for controlling .the fiow of liquid through said air heating unit, and .means for circulating air first in heat exchange relation with said air cooling unit and then in heat exchange relation with said air heating unit.

3. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a

0 multiple compressor having a low pressure suction inlet connected -to the outlet of said freezing evaporator and a high pressure suction inlet connected to the outlet of said air cooling unit, said condenser having its inletconnected to the outlet of said compressor, flow control means for controlling the flow of liquid refrigerant from the outlet "of said condenser to said air cooling unit and to said freezing evaporator, said flow control means having a greater total restriction to flow to said freezing evaporator than to said air cooling unit, an electric motor for driving said compressor, first and second switch means connected in parallel electric circuit relationship for controlling the operation of said motor, said first switch means being responsive to the temperature of the liquid in the liquid heating unit and being set to close at a; predeterm'ined low temperature and to open ata-predeterminedhigh temperature, said second switch meansbeing responsiveto the temperature of said freezing-evaporator and being set to open at a predetermined low-temperature and to close at a predetermined high temperature, said liquid heating unit including a liquid heat transfer circuit extending between the condenser and the liquid to be heated and having an electrically operated pump connected in said circuit for circulating liquid through the circuit, said pump being electrically connected in parallel electric circuit relationship with said compressor.

4. Refrigerating apparatus including an insulated freezing unit-having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heat-ingunit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet connected to the outlet of said freezing evaporator and a high pressure suction inlet connected to the outlet of said air cooling unit, said condenser having its inlet connected to the outlet of saidcompressor, flow control means for controlling the flow of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said flow control means having a greater total restriction to flow to said freezing evaporator than to said air cooling unit, an electric motor for driving said compressor, said liquid heating unit including a tank having spaced bottom walls, and conduit means extending in heat transfer relationship with said condenser connected to the space between said bottom walls of said tank to form a closed heat transfer system, said conduit means and said space containing a heat transfer liquid.

5. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet connected to the outlet of said freezing evaporator and a high pressure suction inlet connected to the outlet of said air cooling unit, said condenser having its inlet connected to the outlet of said compressor, a first thermostatic expansion valve connected to the outlet of said refrigerant condenser and having its temperature responsive element in heat exchange relation with the outlet of said air cooling unit, a second thermostatic expansion valve connected to the inlet of said freezing evaporator and having its temperature responsive element in heat exchange relation with the outlet of said freezing evaporator, the outlet of said first valve being connected to the inlets of said air cooling unit and said second valve.

6. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet connected to the outlet of said freezing evaporator and a high pressure suction inlet connected to the outlet of said air cooling unit, said condenser having its inlet connected to the outlet of said compressor, a first thermostatic expansion valve connected to the outlet of said refrigerant condenser and having its temperature responsive element in heat exchange relation with the outlet of said air cooling unit, a second thermostatic expansion valve connected to the inlet of said freezing evaporator and having its temperature responsive element in heat exchange relation with the outlet of said freezing evaporator, and a separating device having its inlet connected to the outlet of said first valve and its lowermost outlet connected to the inlet of said second valve and having another outlet connected to the inlet of said air cooling unit.

7. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a compressor means having suction inlet means connected to the outlet of said freezing evaporator and to the outlet of said air cooling unit, said condenser having its inlet connected to the outlet of said compressor means,

flow control means for controlling the flow of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said flow control means having a greater total restriction to flow to said freezing evaporator than to said air cooling unit, an air heating unit having its inlet and outlet connected to said liquid heating unit, and a thermostatic valve set to open at a predetermined high liquid temperature in said liquid heating unit for controlling the flow of liquid through said air heating unit.

8. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet continuously connected to the outlet of said freezing evaporator and a high pressure suction inlet continuously connected to the outlet of said air cooling unit, said condenser having its inlet continuously connected to the outlet of said compressor, flow control means for controlling the flow of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said flow control means including a thermostatic expansion valve located at the inlet of said freezing evaporator, said valve being provided with a thermostat bulb located in heat exchange relation with the outlet of said freezing evaporator.

9. Refrigerating apparatus including an insulated freezing unit having a freezing evaporator, an air cooling unit operating at temperatures above freezing, a liquid heating unit including a refrigerant condenser in heat exchange relation with the liquid to be heated, a multiple compressor having a low pressure suction inlet continuously connected to the outlet of said freezing evaporator and a high pressure suction inlet continuously connected to the outlet of said air cooling unit, said condenser having its inlet continuously connected to the outlet of said compressor, flow control means for controlling the flow of liquid refrigerant from the outlet of said condenser to said air cooling unit and to said freezing evaporator, said flow control means including a thermostatic expansion valve located at the inlet of said freezing evaporator, said valve being provided with a thermostat bulb located in heat exchange relation with the outlet of said freezing evaporator and another thermostatic expansion valve located in series with but preceding the inlet of said air cooling unit, said another valve having its thermostat bulb located in heat exchange relation with the outlet of said air cooling unit.

References Cited in the file of this patent UNITED STATES PATENTS 1,331,600 Wales Feb. 24, 1920 1,786,861 Miller Dec. 30, 1930 1,937,288 McGraw Nov. 28, 1933 1,980,688 Lewis Nov. 13, 1934 2,082,549 Philipp June 1, 1937 2,095,017 Wilkes Oct. 5, 1937 2,161,214 Whitney June 6, 1939 2,162,245 Comstock June 13, 1939 2,249,772 Maniscalco July 22, 1941 2,401,827 Heitchue June 11, 1946 2,492,611 Zearfoss Dec. 27, 1949 2,516,093 Rulf July 18, 1950 2,516,094 Ruff July 18, 1950 2,575,325 Ambrose Nov. 20, 1951

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